Lensless CMOS-Coupled Platform for Miniaturized On-Chip Electrochemiluminescence Imaging and Sensing

Developing compact, sensitive, and fully integrated electrochemiluminescence (ECL) imaging systems is essential for advancing next-generation biosensors and point-of-care (POC) diagnostics. However, conventional ECL platforms typically require bulky, lens-based optical components to capture weak photon emissions, limiting their miniaturization and clinical utility. Here, we present a miniaturized, lensless on-chip ECL imaging platform (ECL-CMOS) that integrates electrochemical sensing directly with a CMOS imaging chip via contact-mode coupling. This architecture significantly enhances photon collection efficiency, expands the imaging field of view, and eliminates the need for external optics or alignment procedures. The system enables spatiotemporal detection of ECL signals from classical reaction pairs, including luminol/H₂O₂ and Ru(bpy)₃²⁺/TPrA, with high sensitivity and reproducibility. As a proof of concept for biomedical applicability, we demonstrate sensitive and quantitative glucose detection in both synthetic and human urine samples. The ECL-CMOS platform offers a scalable, cost-effective, and high-performance solution for real-time biochemical sensing, and holds strong potential for broad deployment in POC diagnostics, environmental analysis, and resource-limited settings.